Occasionally a telephone call will end before all parties to the call are finished speaking. One party may hang up thinking the call has ended, but the other party still has things to say. One of the parties to the call may lose connection to the call or their mobile phone may run out of power. One party may intentionally hang up because they want or need to end the call. Under any of these circumstances, the party that had more to say when the call ended must call back in order to convey their message. If that party cannot call back right away, for whatever reason, they might forget to call back or later forget what they had to say.